org.apache.jackrabbit.oak.spi.state

Interface NodeBuilder

All Known Implementing Classes:

MemoryNodeBuilder, ReadOnlyBuilder, SegmentNodeBuilder

public interface NodeBuilder

Builder interface for constructing new node states.

A node builder can be thought of as a mutable version of a node state. In addition to property and child node access methods like the ones that are already present in the NodeState interface, the NodeBuilder interface contains the following key methods:

• The setProperty and removeProperty methods for modifying properties
• The getChildNode method for accessing or modifying an existing subtree
• The setChildNode and removeChildNode methods for adding, replacing or removing a subtree
• The exists method for checking whether the node represented by a builder exists or is accessible
• The getNodeState method for getting a frozen snapshot of the modified content tree

All the builders acquired from the same root builder instance are linked so that changes made through one instance automatically become visible in the other builders. For example:

     NodeBuilder rootBuilder = root.builder();
     NodeBuilder fooBuilder = rootBuilder.getChildNode("foo");
     NodeBuilder barBuilder = fooBuilder.getChildNode("bar");

     assert !barBuilder.getBoolean("x");
     fooBuilder.getChildNode("bar").setProperty("x", Boolean.TRUE);
     assert barBuilder.getBoolean("x");

     assert barBuilder.exists();
     fooBuilder.removeChildNode("bar");
     assert !barBuilder.exists();
 

The getNodeState method returns a frozen, immutable snapshot of the current state of the builder. Providing such a snapshot can be somewhat expensive especially if there are many changes in the builder, so the method should generally only be used as the last step after all intended changes have been made. Meanwhile the accessors in the NodeBuilder interface can be used to provide efficient read access to the current state of the tree being modified.

The node states constructed by a builder often retain an internal reference to the base state used by the builder. This allows common node state comparisons to perform really.

Method Summary

Modifier and Type	Method and Description
@NotNull NodeBuilder	child(@NotNull String name) Returns a builder for constructing changes to the named child node.
Blob	createBlob(InputStream stream)
boolean	exists() Checks whether this builder represents a node that exists.
@NotNull NodeState	getBaseState() Returns the original base state that this builder is modifying.
boolean	getBoolean(@NotNull String name) Returns the boolean value of the named property.
@NotNull NodeBuilder	getChildNode(@NotNull String name) Returns a builder for constructing changes to the named child node.
long	getChildNodeCount(long max) Returns the current number of child nodes.
@NotNull Iterable<String>	getChildNodeNames() Returns the names of current child nodes.
@Nullable String	getName(@NotNull String name) Returns the name value of the named property.
@NotNull Iterable<String>	getNames(@NotNull String name) Returns the name values of the named property.
@NotNull NodeState	getNodeState() Returns an immutable node state that matches the current state of the builder.
@NotNull Iterable<? extends PropertyState>	getProperties() Returns the current properties.
@Nullable PropertyState	getProperty(String name) Returns the current state of the named property, or null if the property is not set.
long	getPropertyCount() Returns the current number of properties.
@Nullable String	getString(String name) Returns the name value of the named property.
boolean	hasChildNode(@NotNull String name) Checks whether the named child node currently exists.
boolean	hasProperty(String name) Checks whether the named property exists.
boolean	isModified() Check whether this builder represents a modified node, which has either modified properties or removed or added child nodes.
boolean	isNew() Check whether this builder represents a new node, which is not present in the base state.
boolean	isNew(String name) Check whether the named property is new, i.e.
boolean	isReplaced() Check whether this builder represents a node that used to exist but was then replaced with other content, for example as a result of a setChildNode(String) call.
boolean	isReplaced(String name) Check whether the named property exists in the base state but is replaced with other content, for example as a result of a setProperty(PropertyState) call.
boolean	moveTo(@NotNull NodeBuilder newParent, @NotNull String newName) Move this child to a new parent with a new name.
boolean	remove() Remove this child node from its parent.
@NotNull NodeBuilder	removeProperty(String name) Remove the named property.
@NotNull NodeBuilder	setChildNode(@NotNull String name) Adds the named child node and returns a builder for modifying it.
@NotNull NodeBuilder	setChildNode(@NotNull String name, @NotNull NodeState nodeState) Adds or replaces a subtree.
@NotNull NodeBuilder	setProperty(@NotNull PropertyState property) Set a property state
<T> @NotNull NodeBuilder	setProperty(String name, T value) Set a property state
<T> @NotNull NodeBuilder	setProperty(String name, T value, Type<T> type) Set a property state

Method Detail

getNodeState

@NotNull
@NotNull NodeState getNodeState()

Returns an immutable node state that matches the current state of the builder.

Returns:

immutable node state

getBaseState

@NotNull
@NotNull NodeState getBaseState()

Returns the original base state that this builder is modifying. The return value may be non-existent (i.e. its exists method returns false) if this builder represents a new node that didn't exist in the base content tree.

Returns:

base node state, possibly non-existent

exists

boolean exists()

Checks whether this builder represents a node that exists.

Returns:

true if the node exists, false otherwise

isNew

boolean isNew()

Check whether this builder represents a new node, which is not present in the base state.

Returns:

true for a new node

isNew

boolean isNew(String name)

Check whether the named property is new, i.e. not present in the base state.

Parameters:

name - property name

Returns:

true for a new property

isModified

boolean isModified()

Check whether this builder represents a modified node, which has either modified properties or removed or added child nodes.

Returns:

true for a modified node

isReplaced

boolean isReplaced()

Check whether this builder represents a node that used to exist but was then replaced with other content, for example as a result of a setChildNode(String) call.

Returns:

true for a replaced node

isReplaced

boolean isReplaced(String name)

Check whether the named property exists in the base state but is replaced with other content, for example as a result of a setProperty(PropertyState) call.

Parameters:

name - property name

Returns:

true for a replaced property

getChildNodeCount

long getChildNodeCount(long max)

Returns the current number of child nodes.

If an implementation does know the exact value, it returns it (even if the value is higher than max). If the implementation does not know the exact value, and the child node count is higher than max, it may return Long.MAX_VALUE. The cost of the operation is at most O(max).

Parameters:

max - the maximum value

Returns:

number of child nodes

getChildNodeNames

@NotNull
@NotNull Iterable<String> getChildNodeNames()

Returns the names of current child nodes.

Returns:

child node names

hasChildNode

boolean hasChildNode(@NotNull
                     @NotNull String name)

Checks whether the named child node currently exists.

Parameters:

name - child node name

Returns:

true if the named child node exists, false otherwise

child

@NotNull
@NotNull NodeBuilder child(@NotNull
                                    @NotNull String name)
                             throws IllegalArgumentException

Returns a builder for constructing changes to the named child node. If the named child node does not already exist, a new empty child node is automatically created as the base state of the returned child builder. Otherwise the existing child node state is used as the base state of the returned builder.

All updates to the returned child builder will implicitly affect also this builder, as if a setNode(name, childBuilder.getNodeState()) method call had been made after each update. Repeated calls to this method with the same name will return the same child builder instance until an explicit setChildNode(String, NodeState) or remove() call is made, at which point the link between this builder and a previously returned child builder for that child node name will get broken.

Parameters:

name - name of the child node

Returns:

child builder

Throws:

IllegalArgumentException - if the given name string is empty or contains the forward slash character

Since:

Oak 0.6

getChildNode

@NotNull
@NotNull NodeBuilder getChildNode(@NotNull
                                           @NotNull String name)
                                    throws IllegalArgumentException

Returns a builder for constructing changes to the named child node. If the named child node does not already exist, the returned builder will refer to a non-existent node and trying to modify it will cause IllegalStateExceptions to be thrown.

Parameters:

name - name of the child node

Returns:

child builder, possibly non-existent

Throws:

IllegalArgumentException - if the given name string is empty or contains the forward slash character

Since:

Oak 0.7

setChildNode

@NotNull
@NotNull NodeBuilder setChildNode(@NotNull
                                           @NotNull String name)
                                    throws IllegalArgumentException

Adds the named child node and returns a builder for modifying it. Possible previous content in the named subtree is removed.

Parameters:

name - name of the child node

Returns:

child builder

Throws:

IllegalArgumentException - if the given name string is empty or contains the forward slash character

Since:

Oak 0.7

setChildNode

@NotNull
@NotNull NodeBuilder setChildNode(@NotNull
                                           @NotNull String name,
                                           @NotNull
                                           @NotNull NodeState nodeState)
                                    throws IllegalArgumentException

Adds or replaces a subtree.

Parameters:

name - name of the child node containing the new subtree

nodeState - subtree

Returns:

child builder

Throws:

IllegalArgumentException - if the given name string is empty or contains the forward slash character

remove

boolean remove()

Remove this child node from its parent.

Returns:

true for existing nodes, false otherwise

moveTo

boolean moveTo(@NotNull
               @NotNull NodeBuilder newParent,
               @NotNull
               @NotNull String newName)
        throws IllegalArgumentException

Move this child to a new parent with a new name. When the move succeeded this builder has been moved to newParent as child newName. Otherwise neither this builder nor newParent are modified.

The move succeeds if both, this builder and newParent exist, there is no child with newName at newParent and newParent is not in the subtree of this builder.

The move fails if the this builder or newParent does not exist or if there is already a child newName at newParent.

For all remaining cases (e.g. moving a builder into its own subtree) it is left to the implementation whether the move succeeds or fails as long as the state of the involved builder stays consistent.

Parameters:

newParent - builder for the new parent.

newName - name of this child at the new parent

Returns:

true on success, false otherwise

Throws:

IllegalArgumentException - if the given name string is empty or contains the forward slash character

getPropertyCount

long getPropertyCount()

Returns the current number of properties.

Returns:

number of properties

getProperties

@NotNull
@NotNull Iterable<? extends PropertyState> getProperties()

Returns the current properties.

Returns:

current properties

hasProperty

boolean hasProperty(String name)

Checks whether the named property exists. The implementation is equivalent to getProperty(name) != null, but may be optimized to avoid having to load the property value.

Parameters:

name - property name

Returns:

true if the named property exists, false otherwise

getProperty

@Nullable
@Nullable PropertyState getProperty(String name)

Returns the current state of the named property, or null if the property is not set.

Parameters:

name - property name

Returns:

property state

getBoolean

boolean getBoolean(@NotNull
                   @NotNull String name)

Returns the boolean value of the named property. The implementation is equivalent to the following code, but may be optimized.

 
 PropertyState property = builder.getProperty(name);
 return property != null
     && property.getType() == Type.BOOLEAN
     && property.getValue(Type.BOOLEAN);
 
 

Parameters:

name - property name

Returns:

boolean value of the named property, or false

getString

@Nullable
@Nullable String getString(String name)

Returns the name value of the named property. The implementation is equivalent to the following code, but may be optimized.

 
 PropertyState property = builder.getProperty(name);
 if (property != null && property.getType() == Type.STRING) {
     return property.getValue(Type.STRING);
 } else {
     return null;
 }
 
 

Parameters:

name - property name

Returns:

string value of the named property, or null

getName

@Nullable
@Nullable String getName(@NotNull
                                   @NotNull String name)

Returns the name value of the named property. The implementation is equivalent to the following code, but may be optimized.

 
 PropertyState property = builder.getProperty(name);
 if (property != null && property.getType() == Type.NAME) {
     return property.getValue(Type.NAME);
 } else {
     return null;
 }
 
 

Parameters:

name - property name

Returns:

name value of the named property, or null

getNames

@NotNull
@NotNull Iterable<String> getNames(@NotNull
                                            @NotNull String name)

Returns the name values of the named property. The implementation is equivalent to the following code, but may be optimized.

 
 PropertyState property = builder.getProperty(name);
 if (property != null && property.getType() == Type.NAMES) {
     return property.getValue(Type.NAMES);
 } else {
     return Collections.emptyList();
 }
 
 

Parameters:

name - property name

Returns:

name values of the named property, or an empty collection

setProperty

@NotNull
@NotNull NodeBuilder setProperty(@NotNull
                                          @NotNull PropertyState property)
                                   throws IllegalArgumentException

Set a property state

Parameters:

property - The property state to set

Returns:

this builder

Throws:

IllegalArgumentException - if the property name is empty or contains the forward slash character

setProperty

@NotNull
<T> @NotNull NodeBuilder setProperty(String name,
                                              @NotNull
                                              T value)
                                       throws IllegalArgumentException

Set a property state

Type Parameters:

T - The type of this property. Must be one of String, Blob, byte[], Long, Integer, Double, Boolean, BigDecimal

Parameters:

name - The name of this property

value - The value of this property

Returns:

this builder

Throws:

IllegalArgumentException - if T is not one of the above types, or if the property name is empty or contains the forward slash character

setProperty

@NotNull
<T> @NotNull NodeBuilder setProperty(String name,
                                              @NotNull
                                              T value,
                                              Type<T> type)
                                       throws IllegalArgumentException

Set a property state

Type Parameters:

T - The type of this property.

Parameters:

name - The name of this property

value - The value of this property

Returns:

this builder

Throws:

IllegalArgumentException - if the property name is empty or contains the forward slash character

removeProperty

@NotNull
@NotNull NodeBuilder removeProperty(String name)

Remove the named property. This method has no effect if a property of the given name does not exist.

Parameters:

name - name of the property

createBlob

Blob createBlob(InputStream stream)
         throws IOException

Throws:

IOException